Itaconic acid-modified triglyceride shortening composition and method of preparing the same



ITACONIC ACID-MODIFIED TRIGLYCERIDE SHORTENING COMPOSITION AND METH- OD OF PREPARING THE SAME John J. Gleason, Cedar Falls, Iowa, assignor to The Rath IPacking Company, Waterloo, Iowa, a corporation of owa No Drawing. Filed Dec. 14, 1959, Ser. No. 859,136 7 Claims. (Cl. 99-118) This invention relates to improved shortening compositions especially useful for preparing bakery products, such as cakes. The shortening compositions are characterized by improved creaming ability, storage stability and emulsifying properties. Cakes containing the shortening of the invention have a fine uniform texture, are extremely light, and remain moist for four or five days after baking, even when exposed to air.

The compositions consist of edible triglyceride fats which have been modified by the substitution, for an originally fatty acid radical, of an ethylene carboxylic acid radical, effected by reacting the fat with itaconic (propylenedicarboxylic) acid.

Edible animal and vegetable triglycerides (containing no substantial quantities of monoand diglycerides) which are commonly used as shortenings may be used in the preparation of the shortening compositions of the invention. Such shortenings, modified by reaction with itaconic acid, are preferably mixed with an untreated glyceride shortening to prepare a commercial shortening product.

In a preferred form of the invention the triglyceride fat, for example lard, is molecularly rearranged in the presence of an interesterification catalyst at a temperature slightly above room temperature for a period of time ranging from two to sixty minutes, in the absence of air. From 0.1% to 4% by weight of the itaconic acid is added to the rearranged material. This quantity of acid permits substitution on the average in about one out of every three to one hundred molecules of the triglyceride. Expressed in terms of moles, I may use from .01 to .3 moles of the acid for each mole of fat. After adding the itaconic acid, the reaction is continued under the same conditions for an additional one-half to three hours. It appears that the ethylene carboxylic acid radicals replace some of the fatty acid radicals normally present in the triglyceride. This is substantiated by the fact that the free fatty acid content of the end product (before washing) is increased considerably over that of the original triglyceride fat. The exact nature of the molecular rearrangement and the acid radical substitution is not completely understood. Experts in the art are not in accord as to whether the initial reaction here referred to and which takes place in the presence of the catalyst actually causes the fatty acid radicals to change places with each other (interesterification) or whether isomers are formed in some other manner. The chemistry of the fatty materials is complex. It will be appreciated that in dealing with any naturally occurring substance, such as animal and vegetable fats, the chemical composition of the original material will vary considerably. Consequently, the end product cannot be accurately identified either with respect to the rearrangement or interesterification that takes place or as to the precise way in which the itaconic acid adds to the fat. Nevertheless, the reaction as defined does provide a greatly improved plastic shortening having a good consistency over a relatively wide temperature range in addition to the greatly improved emulsifying property.

My invention also may be carried out by adding the itaconic acid to the triglyceride fat before any molecular rearrangement has occurred. In other words, the acid is added to the fat first, followed by addition of the catalyst and raising the temperature to bring about rearrangement and substitution simultaneously.

The fatty acids suitable for use in the invention include lard, tallow and hydrogenated vegetable oils such as cottonseed, soya, coconut, corn, peanut and the like.

The temperatures at which the reaction takes place may range from room temperature to 200 C. At the higher temperatures the reaction, of course, is carried out completely in the liquid phase. I prefer, however, to carry out the reaction at a temperature below that at which the liquid phase is saturated with respect to the relatively high melting triglycerides present in the fat so that such high melting triglycerides formed during the interchange of fatty acid radicals will crystallize from the liquid fat and take no further part in the rearrangement process. When molecules of low solubility in the liquid fat phase are formed and crystallize out, further rearrangement of such molecules is prevented. The preferred temperature range is from room temperature to about 50 C., depending upon the particular fat being treated and the type and quantity of catalyst used. It is apparent that the melting point of the fat will determine the precise temperature range employed. The temperature is preferably not raised above the point at which some of the fat remains in the solid phase. Stated conversely, at least some of the fat will be in the liquid phase.

The time of reaction will vary from thirty minutes to six hours, preferably from two to four hours depending upon the temperature, concentration and nature of the catalyst and the particular triglyceride fat being treated. The invention contemplates the use of well known catalysts, such as the alkali metal alcoholates and inorganic salts. Suitable inorganic salts are stannous chloride, zinc acetate, zinc oxide, lead acetate, cobalt nitrate, ferrous hydroxide, bismuth nitrate and titanium tetrachloride. The quantity of catalyst used may range from slightly more than zero up to 1% to 2%. Over 1% the accelcrating effect of the catalyst begins to wane. One of the most effective catalysts is sodium methylate.

Although the acid-modified triglyceride shortening may be used alone in certain applications, I prefer to mix it to the extent of 3% to 50% by weight with another shortening not so modified. The mixture is particularly suitable for bakery products.

The following example illustrates the invention.

One thousand grams of vacuum dried, caustic refined lard were mixed with .2% sodium methylate catalyst and permitted to undergo rearrangement for about two minutes. Two percent edible itaconic acid by weight was then added to the lard and the reaction was continued for two hours in vacuo at a temperature ranging not higher than 30 C. At the end of this period the catalyst was removed by water washing the end product three times, drying under vacuum and bleaching. The cooling curves indicated that the molecular rearrangement of the lard had been effectively completed. The normal crystal habit of the lard was completely modified. The end product exhibited remarkable creaming and emulsifying properties.

To test the effectiveness of the modified shortenings prepared in accordance with the foregoing example, cakes were baked using the modified shortening in comparison with a shortening which was not modified by reaction Percent By A Weight Itaconic acid rearranged lard Unmodified rearranged lard Cake batters were prepared using a commercial dry cake mix and shortening compositions A and B. After the cakes were baked, the cake volume, the grain and the conformation were determined with the following results:

Sample Grain Coniorma- Volume tion 'B-Control Fair Good 265 A-Shortentng ModifiedwithProd- Good Good 324 not of Example.

After five days exposure to the atmosphere, the control cake was dry and hard whereas the cakes employing the shortening of the invention had retained their softness and moisture.

This application is a continuation-impart of my copending application Serial No. 660,043, filed May 20, 1957, now abandoned.

It will be apparent to those skilled in the art that various modifications may be made in carrying out the reactions of the invention without departing from the spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An improved edible shortening composition prepared by molecularly rearranging a triglyceride fat substantially free of monoand diglycerides in the presence of an interesterification catalyst at a temperature at which at least some of the fat remains in the liquid phase, adding from 0.1% to 4% by weight of itaconic acid, and continuing the reaction under the same conditions to cause substitution of the ethylene carboxylic acid radical of said itaconic acid for some of the fatty acid radicals originally present in the triglyceride fat.

2. An improved edible shortening composition prepared by molecularly rearranging a triglyceride fat substantially free of monoand diglycerides in the presence of from 0.1% to 4% by weight of itaconic acid to cause substitution of the ethylene carboxylic acid radical for some of the fatty acid radicals originally present in the triglyceride fat, the reaction being carried out in the presence of an .interesterification catalyst and at a temperature at which some of the triglyceride fat remains in the solid phase.

3. The composition of claim fat is lard.

4. A mixture of 3% to 50% of the shortening .of claim 1 and an edible glyceride shortening.

5. A mixture of 3% .to 510% of theshortening of claim 3 and an edible glyceride shortening.

6. A method for preparing an improved edible shortening which comprises rearranging a triglyceride fat substantially free of monoand diglycerides by heating said triglyceride fat to a temperature at which all of the constituents thereof are molten, said heating being carried out in the presence of less than 1% by weight of sodium .methylate catalyst, adding from 0.1% to 4% by .1 wherein the triglyceride weight of 'itaconic acid and continuing the reaction at said temperature until the ethylenic carboxylic acid radical of said quantity of acid added has replaced the fatty acid radical in some of the triglyceride molecules of said fat.

7. An improved edible shortening composition prepared by molecularly rearranging a triglyceride fat substantially free of monoand diglycerides in the presence of from 0.1% to 4% by weight of itaconic acid to cause substitution of ethylenic carboxylic acid radicals for some of the fatty acid radicals originally present in the triglyceride fat, the reaction being carried out at a temperature at which all of the at is in the liquid phase 'but below 200 C. and in the presence of an interestedfication catalyst.

References Cited in 'the tile of this patent UNITED STATES PATENTS 2,378,006 Eckey June 12, 1945 2,442,532 Eckey June 1, 1948 2,480,332 Little Aug. 30, 1949 2,509,414 'Barsky May 30, 1950 2,690,971 Iveson et al Oct. '5, 1954 

1. AN IMPROVED EDIBLE SHORTENING COMPOSITION PREPARED BY MOLECULARLY REARRANGING A TRIGLYCERIDE FAT SUBSTANTIALLY FREE OF MONO- AND DIGLYCERIDES IN THE PRESENCE OF AN INTERESTERIFICATION CATALYST AT A TEMPERATURE AT WHICH AT LEAST SOME OF THE FAT REMAINS IN THE LIQUID PHASE, ADDING FROM 0.1% TO 4% BY WEIGHT OF ITACONIC ACID, AND CONTINUING THE REACTION UNDER THE SAME CONDITIONS TO CAUSE SUBSTITUTION OF THE ETHYLENE CARBOXYLIC ACID RADICAL OF SAID ITACONIC ACID FOR SOME OF THE FATTY ACID RADICALS ORIGINALLY PRESENT IN THE TRIGLYCERIDE FAT. 